This invention presents an energy converter to recover and combine diverse motor vehicle energy sources for supplying compressed working fluid to a motor vehicle prime mover, wherein a liquefied air portion of the working fluid provides pre-compression cooling of an atmospheric air portion thereof; the liquefied air being made by recovered energy, stored and transferred between vehicles and between vehicles and stationary sites.
Increased fuel mileage and range in conjunction with low grade fuels has long been a goal of automotive design, to make driving more economical, to conserve fossil fuels, and to reduce emission of combustion products. Recovery and combining of vehicle energy sources as available, including kinetic (deceleration and shock), wind resistance, and solar radiation, is not described in the prior art. In addition, coordinated storage and transfer of recovered energy using pneumatic, cryogenic and electric systems is not described in the prior art. Recovery of only the deceleration component of kinetic energy, coordinated with electrical transfer between batteries and generators, is used in lightweight hybrid vehicles to provide limited performance improvement. Relevant vehicle energy recovery and consumption devices described in the prior art have disadvantages, as follows:
(a) U.S. Pat. No. 1,671,033 to Kimura (1928) describes a transmission with an electric generator and battery storage for recovery of vehicle deceleration, the component of vehicle kinetic energy in the direction of travel. The recovered energy, normally dissipated by engine compression and vehicle braking, is stored in batteries and used for limited electrical power assist. Deceleration energy is not completely recoverable due in part to insufficient battery capacity.
(b) U.S. Pat. No. 3,688,859 to Hudspeth and Lunsford (1972) describes compressors connected between the frame and axles of a vehicle for recovery of shock, the upward component of vehicle kinetic energy. The recovered energy, normally dissipated by shock absorbers, is used for limited pneumatic power assist. Shock energy is not completely recoverable due to compression heating.
(c) U.S. Pat. No. 6,138,781 to Hakala (2000) describes an electric generator for recovery of vehicle wind energy. The recovered energy, normally dissipated by vehicle drag force, is used for limited electrical power assist. Potential wind energy recovery is not realized because air from a wind recovery device is discharged to relatively high wake pressure. In addition, aerodynamic vehicle shapes are often used to reduce drag loss at the expense of vehicle function, such as carrying capacity.
(d) U.S. Pat. No. 5,725,062 to Fronek (1998) describes the use of a solar photo-voltaic panel atop a vehicle for recovery of solar energy radiating to a vehicle. The recovered energy, normally dissipated to the atmosphere, is used for limited electrical power assist. Solar radiation to a vehicle is not completely recoverable due in part to insufficient battery capacity.
(e) U.S. Pat. No. 4,182,960 to Reuyl (1980) describes transfer of electrical energy between vehicles and stationary sites. Solar energy recovered at a site is stored in batteries to provide power to the site and a portion is transferred to, and stored in batteries in a hybrid gas turbine-electric vehicle. The gas turbine can provide power to the site via an electric generator to supplement site solar energy. Battery storage problems include space and weight limitation, trade-off between battery life and energy discharged, replacement handling, charge time, and ventilation.
Research programs at the University of Washington (“Ultra-Low Emission Liquid Nitrogen Automobile” Knowlen, Mattick, Hertzberg, and Bruckner, SAE-1999-0102932, 1999) and the University of North Texas (“Cryogenic Heat Engines for Powering Zero Emission Vehicles”, Ordonez, Plummer, and Reidy, IMEECE2001/PID-25620, 2001) describe a liquefied gas system to supply liquid nitrogen for on-board storage and use in zero emissions vehicles powered by ambient temperature heat engines. Transfer of liquefied gas between vehicles and from vehicles to stationary sites, for use thereof, is not described in the prior art. Liquefied gas transfer problems include boil-off and fill and drain connection.
(f) The prior art describes several types of gas liquefiers including; vapor-compression, magnetic, Stirling cycle and thermo-acoustic, for stationary application. State-of-the-art air liquefiers require compression work of approximately 2.5 times the heat removed per 2.2 kg (1 lb) of air liquefied.
(g) Gas turbine engine powered vehicles are described in the prior art and were produced by Rover and by Chrysler Corporation during the 1950's and 1960's. Gas turbine engines require high turbine inlet temperature to provide acceptable thermal efficiency. Other problems include high compression work, high turbine blade and exhaust gas temperature, and expensive heat exchangers. Operation is characterized by falling efficiency with load and compression braking is unavailable. Low grade fuels such as kerosene can be burned, however emissions are high due to high fuel consumption and formation of compounds at high temperature.
(h) U.S. Pat. No. 4,294,323 to Boese (1981) describes a gas expander using cryogenic liquid working fluid. Cryogenic expanders have low specific expansion energy due to heat input at ambient temperature. Research programs at the University of Washington (“Ultra-Low Emission Liquid Nitrogen Automobile” Knowlen, Mattick, Hertzberg, and Bruckner, SAE-1999-0102932, 1999) and at the University of North Texas (“Cryogenic Heat Engines for Powering Zero Emission Vehicles”, Ordonez, Plummer, and Reidy, IMEECE2001/PID-25620, 2001) describe development of liquid nitrogen expanders with emphasis on maximizing output by designing for quasi-isothermal expansion. Expanders have limited usefulness in lightweight, short range, low speed vehicles for zero emission urban use.
(i) U.S. Pat. No. 3,525,874 to Toy (1970) describes a hybrid gas turbine-electric prime mover, and U.S. Pat. No. 3,566,717 to Berman (1971) describes a hybrid transmission for parallel operation of a combustion engine and an electric motor. Recovered deceleration energy, normally dissipated by engine compression and vehicle braking, is stored in batteries and used for power assist in hybrid vehicles. Combustion engine efficiency is low, and deceleration is not completely recoverable due in part to insufficient battery capacity.